Online Photo Diagnosis

By William Townsend, OD, FAAO

This 22-year-old female presented complaining of asymmetric bilateral injection and irritation, with a scant discharge. Over the previous six weeks, she had seen several other healthcare providers for this condition. They had prescribed topical antibiotics, none of which really alleviated her symptoms. On examination, I noted punctate keratitis, the large follicles apparent in the photo, and mild conjunctival injection. She had bilateral, non-tender preauricular adenopathy. The patient admitted that she was currently sexually active with one partner. Based on the history and our findings, I diagnosed adult inclusion conjunctivitis and referred the patient to her primary care provider for lab testing and consultation. He confirmed our diagnosis and treated the patient and her partner with a five-day course of azithromycin.

Chlamydia trachomatis is an intracellular obligate bacterium that infects mucous membranes of the eye and genitalia and, depending on the serotype, causes three clinical syndromes: classic trachoma, adult inclusion conjunctivitis (AIC), and neonatal inclusion conjunctivitis. AIC is the most commonly reported form of bacterial sexually transmitted disease, followed by gonorrhea. Approximately 2.8 million new cases of Chlamydia are reported in the United States each year. It is the most frequent cause of pelvic inflammatory disease, an infectious and inflammatory disease of the female reproductive organs that often causes scarring of the fallopian tubes and is a common cause of infertility. Many individuals who have genital complications of AIC are totally unaware of their condition; three-quarters of infected women and about half of infected men have no symptoms. When symptoms occur, they usually do so within three weeks of infection. It is estimated that 1 in 300 patients who have genital chlamydial disease develop AIC.

AIC is the most common cause of chronic follicular conjunctivitis. Other causes of follicular conjunctivitis include long-standing adenoviral infection, toxic follicular conjunctivitis from medications or Molluscum contagiosum, and folliculosis in children. Given the potential for infertility and other sequelae of AIC, you should pursue and, if possible, identify the causative agent in any patient who has chronic follicular conjunctivitis, especially in females of childbearing age. The definitive diagnosis is made with laboratory testing, although empirically treating suspected AIC patients is a common and practical approach.

The recommendations for laboratory confirmation of the Association of Public Health Laboratories is as follows:

• Nucleic acid amplification tests are recommended for detection of reproductive tract infections caused by C. trachomatis and N. gonorrhoeae infections in men and women with and without symptoms.• Optimal specimen types for nucleic acid amplification tests are first catch urine from men and vaginal swabs from women.

Use of enzyme linked immuno-assay tests such as the Chlamydiazyme (CZ) system often result in high false positive results for many non-Chlamydia bacteria found in the genitourinary tract. One study showed false positive CZ values of 47 percent for Escherichia coli and 100 percent for Klebsiella pneumoniae. Using Geisa stain, cell cultures infected with Chlamydia show inclusion bodies within the cellular cytoplasm. This technique provides definitive diagnosis but is expensive and requires several days to obtain results.

Treat AIC by eradicating the bacteria with systemic antibiotic therapy. It is very important that all sexual partners be treated as well to reduce the incidence of re-infection. Topical medications provide minimal benefit; systemic therapy is prescribed for three to six weeks and includes oral tetracycline (500 mg qid), oral doxycycline (100 mg bid), or oral erythromycin (500 mg qid). Tetracyclines should be avoided in children younger than 13 years of age and in women who are pregnant or nursing. Azithromycin can be given as a single dose of 1 gm, or in the familiar "Z-pak." Patients should be re-evaluated in one month to ensure that the treatment has been successful and no re-infection has occurred